Study On Preparation And Performance Of Metal Mesh/Polymer Composite Functional Filter Membrane

Water treatment technology based on membrane has been widely researched and applied in the field of water treatment due to its advantages such as high separation efficiency,good effluent quality,and simple equipment operation.However,the serious membrane fouling problem in the operation process restricts the development of membrane technology and becomes the bottleneck of membrane technology.The chemical off-line cleaning often used after membrane fouling is not only cumbersome,can cause irreversible damage to the membrane surface,but also leads to secondary pollution;in addition,the existing membrane technology separates the substances,and its function is single,which is difficult to effectively recycle some resource materials.In this study,polypyrrole and polyaniline were used to modify the stainless steel mesh substrate to prepare a composite conductive filter membrane.The conductive filter membrane was used to control membrane fouling by backwashing during power on.Using its electrochemical properties to achieve the purpose of resource material recovery,the main research contents are as follows:(1)Using electrochemical polymerization method,the stainless steel mesh substrate with a filtration accuracy of 4?m was prepared by electrochemical cyclic voltammetry in the pyrrole and aniline monomer solutions of the specified concentration to prepare polypyrrole and polyaniline/stainless steel mesh composite conductive filter membrane,by adjusting the number of cyclic voltammetry scans,the flux range of the two composite filter membranes is controlled at 600-2000L/(m2·h·bar),and the excellent filtration function of the composite filter membrane is realized.The prepared composite filter membrane has good electrical conductivity,filtration performance,structural stability and electrochemical stability.(2)In order to study the effect of composite conductive filter membrane on the interception of pollutants and the control of backwash membrane fouling during power on.The standard simulated pollutant(sodium alginate,bovine serum protein and humic acid)solution and the actual secondary effluent were used for filtration and backwash cycle experiments respectively.The results show that the composite conductive filter membrane has a good effect of intercepting organic matter,and the control of membrane fouling is strengthened.The composite conductive filter membrane was used as the cathode,the graphite rod was used as the anode,and 0.1mol/L sodium chloride was used as the backwashing solution.When the voltage of 2V was applied,the membrane flux recovery rate was significantly better than that of the control group.Studies have shown that expansion of the surface of the composite filter membrane after power on,the increase in hydrophilicity,the generation of bubbles,and the formation of electric field polarization all significantly improve the control effect of membrane fouling.(3)In order to study the adsorption and recovery of the phosphorus resource by the polyaniline composite filter membrane,phosphorus adsorption and desorption studies were carried out using phosphorus standard solution and actual secondary effluent.The adsorption capacity is 0.0457mg/cm2 when it is not power on;when the voltage is 5V,the desorption effect reaches more than 98%,and the adsorption and desorption are repeated 5 times,and the polyaniline composite filter membrane still has good adsorption and desorption capabilities.The above research shows that the preparation of composite filter membrane by electrochemical polymer based on stainless steel mesh provides a novel idea for filter membrane development and preparation;the application of electric field by the stainless steel mesh cathode membrane can effectively improve the membrane pollution control effect,and the operation is simple and have obvious economic and environmental benefits.The process of using polyaniline conductive filter membrane to adsorb and desorb the resource substance phosphorus(P)and carry out recovery and concentration provides technical guidance significance for the functional development of separation membrane.